During the fourteenth year of support, Program-project 08682 investigators studied mechanisms of cardiovascular regulation with specific emphasis from many different points of view, including central, spinal and peripheral nervous control, biochemical and metabolic regulation, endotoxin shock, cardiopulmonary integration, renal hypertension, transmembrane ion transport, catecholamine metabolism, neural activation of the renin-angiotensin system, dynamics of pulmonary circulation and the regulation of hibernation and arousal. Emanating from the research are descriptions of animal models of cardiac dysrhythmia based upon surgically imbalanced autonomic innervation of the heart, the function of subsidiary atrial pacemakers in the absence of the SA node, and structure-functional descriptions of spinal pathways mediating cardiovascular reflexes. Papers describing plasma renin concentraitons after total cardiac denervation, uptake of ATP by liver and kidney in hemorrhagic shock, the sympathetic preganglionic neurons in the spinal cord, mechanical properties of human mammary arteries and saphenous veins and their implications for coronary artery bypass, and counter insulin therapy in endotoxin shock illustrate the output of the program. In addition, depression of RES function and altered glucoregulation, sympathetic modulation of canine AV nodal conduction, the role of descending pressor pathways in the conscious dog, myocardial norepinephrine and lactate changes in arousal from hibernation and hypothermia, and the chemical characterization of hibernation including "trigger" were described. Sodium and potassium transport during endotoxin and hemorrhagic shock, histofluorescence and chemical analysis of myocardial catecholamines during regeneration of sympathetic neurons, and the anatomical organization of the phrenic nucleus are being pursued.